题目

人体呼出的气体和吸入的气体相比，其变化是( )①温度升高 ②水分增多 ③氧气含量升高 ④二氧化碳含量升高A. ①②③ B. ①②④ C. ②③④ D. ①③④ 答案：【答案】B【解析】人体呼出的气体和吸入的气体相比温度升高，水分增多，二氧化碳含量升高，氧气含量降低。故选B。— How many students have seen the new film in your class? — ______. [     ]A. Both B. Everyone C. Someone D. None